The present invention relates to an electrochemical device with high-efficiency purification. The main structure includes a plurality of reaction tanks, a plurality of power supply elements respectively disposed on the reaction tanks, at least one connection member connecting the reaction tanks in series or in parallel with each other, and a reaction tank. A first receiving tank inside, at least one second receiving tank provided in the reaction tank and communicating with the first receiving tank, an electrochemical module provided in the first receiving tank, and at least one provided in the first receiving tank The water treatment module in the two containing tanks, wherein the electrochemical module includes at least one carbon-based element, at least one catalyst element, and at least one conductive element. In this way, the characteristics of the electrochemical module and the water treatment module can be freely combined in the reaction tank, and the action of multiple reaction tanks connected in series or in parallel is used to control the quality, efficiency and output of the highly reactive oxygen species produced. .
